Thermostatic control means



Dec. 15', 1942.

J. C. ENGLISH THERMOSTATIC CONTROL MEANS Filed April 2, 1940 m a mfi N M m V/. l mw r z A $6 w mema net. 15, 1942 rnnamos'ra'rlc CONTROL MEANS 101m 0. English, Cedar Rapids, Iowa, assig'nor to Johnson Gas Appliance Company, Cedar Rapids, Iowa, a corporation of Delaware Application April 2, 1940, Serial N0.- 327,399

1 Claim. (Cl- 158-1174) This invention relates to fluid fuel burners and has particular relation to an ignition and control means for such burners.

One of the main or general objects of my invention is to provide an ignition and control sys- 'tem for fluid fuel burners such as gas burners,

which will ignite the gas every time the gas is turned on, regardless of how long the unit has been in operation previously or how long the gas has been off.

Another general object of my invention is to providea control or safety system operative by small diflerences of fuel pressure for preventing opening of the main fuel supply valve until igni-- tion is assured, for furnishing ignition to a pilot burner, for regulating the supply of fuel to the pilot burner, and for turning off the main fuel supply valve in the event of failure of the pilo burner.

More specifically, one of the main objects of my invention is to provide means whereby oxidation, fouling and the like of the parts of such a system will not hinder or otherwise aii'ect its operation. v

Another object of my invention is to provide, in a control system of the above .character, a new i4 fills the chambers i6 and I I. The gas in chamber i'l closes the switch I? to energize the transformer l8 and provide aspark at the spark gap l9 between the electrode 2! and the body of the pilot burner 22.

The pilot burner is mounted upon or comprises part of a throttle valve housing 23 which houses the throttle valve 24. Gas admitted to the chamber ii of the main valve housing Ilia flows through the conduit 26 into chamber 21 of the throttle valve housing, through the port 28 controlled by the throttle valve 24, mm chamber 29,

and improved throttling valve, thermostat, and

pilot burner structure.

Another important object of my invention is to provide a packless valve suitable for controlling the flow of fluids in a system from outside the system without leakage and without interference by corrosion, fouling and the like.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawing and following specifications,

wherein is disclosed a single exemplary embodiment of the invention, with the understanding,

however, that such changes may be made therein as fall within the scope of the appended claims, without departing from the spirit of the invention.

The single figure of the drawing is a schematic .diagram of one embodiment of the invention with portions of the devices shown in plan view and other portions in section, and illustrating a preand back through a conduit 30 to a chamber 3| beneath the'diaphragm 32 of the control valve. This immediately equalizes the pressure on the opposite sides of the diaphragm 32 and prevents the main control valve H from opening. The

spring 33 ordinarily holds the valve ii in the closed position if there is no difference in pressure .on the opposite sides of the diaphragm.

Gas may pass from the chamber 29 on the output side of the throttle valve 24, through the bore 34 in the jet 35, and out through the orifice 36. Gas issuing from this orifice 36 sucks air in from outside the oven or other enclosure through the secondary air conduit 31, and the mixture of air and gas passes through the pilot burner ports 38 and is ignited by the spark at gap IS.

A thermal element 39, which may be approximately' triangular in shape, is supported in front of the flame of the pilot burner by means of a lug 4i on the throttle valve housing. This thermostatic element is preferably of a single strip of metal, such as stainless steel, bent back upon itself and having the ends of the strip fastened to each other and to the lug 4 i' by means of a screw 42. The straight portions forming the sides of the triangle are preferably flanged for stiffness; but the comers of the strip may bend and flex readily so that, when the element is unequally heated, as by means of the flame from the pilot burner striking the long leg 39a, the short legs 39?; and 39c move inwardly and the comers of the triangular shaped element flex to cause in-' ward movement of the lever arm 43, which is a continuation of the side 3912.

The lever arm 43 has a yoke-like end portion 43a which is adapted to engage the flattened portion 44a of a toggle pin or rod 44. This toggle rod or valve stem is fastened securely to the phagm is held in place on-the throttle valve housing 23 by means of a cap 23a and screws 23b. The inner end of the toggle arm 44 is pivotally secured to a small clevis member 41 which is threaded 'to receive the threaded stem of the the parts, once secured, is not thereafter aiIected by oxidation or change in the metal structure or the like. The diaphragm aflords a complete seal for the chamber 21 and no unburned gas can escape from this chamber nor any foreign impurities enter.

The inward movement of the free end of the lever arm 43 produces outward movement of the inner end of the toggle armand thus causes the throttle valve 24 to move in the port 28 to partially close of! the port and-throttle the gas passing through the port. This throttling of the gas reduces the pressure-beyond the throttle valve, thereby reducing the amount of gas issuing from the orifice l6 'andpllot burner ports 38, and also reduces the pressure in the chamber 3| beneath the main valve diaphragm l2 and permits the pressure of the gas in the chamber it to overcome the pressure of the spring 33 and open the main control valve II to permit gas to flow into the chamber Ila and into the main burner II through the conduit 52. The gas now present in the output port Ila of the control valve Ii and in the conduit 52 passes through a small conduit 53 to the chamber 54 beneath the switch actuating diaphragm it. to thus equalize the on opposite sides of the diaphragm to open the switch 12 and thus de-energize the ignition transformer.

If, for any reason, the pilot burner goes out, the long leg 29a of the thermostat l9 contracts and the lever arm moves outwardly to open the throttling port 28 to again equalize the pressure on the opposite sides of the diaphragm 32 and permit the spring 33 to close the control valve.

The same action occurs if the shut-off valve I3 is closed-that is, the pressure on theopposite sides of the diaphragm 32 is almost instantly equalized by bleeding of the gas through the throttling valve, and the control valve II is closed and made ready for the next cycle of operation.

It is apparent that the opening of the shutof low pressure or the like, the flow of gas to the main burner is shut off.

It is apparent that I have devised a new and improved control means includinga "packless" valve particularly suitable for controlling the flow of fluid in a system by actuating means outside the system so that no leakage of the fluid occurs and operation of the valve is not affected by oxidation, fouling and the like. The

valve may be used in controls for radiators,-

poisonous gases, liquids and the like, without danger through leakage.

Although I have described a specific embodiment of my invention, it is apparent that modifications thereof may be made by those skilled in the art. Such modifications may be made without departing from the spirit and scope of my invention as set forth in the appended claim.

I claim as my invention:

In a fluid fuel control means, tire combination of a main burner, a diaphragm actuated fuel flow control valve, a suppLv line for the valve, a first conduit for conducting fluid fuel under pressure direct from the supply line independent of said control valve to one side of the diaphragm of the valve, a pilot burner connected to receive fuel from the supply line a normally open throttle valve, a housing therefor connected on one side with the supply line and on its other side with the pilot burner and the other side of said diaphragm, whereby pressure of the fluid fuel on said other side of the diaphragm of the control valve may be relieved by throttling of said throttle valve to permit the control valve to open, and the fuel supply to the-pilot burner to be reduced, means for operating the throttle valve comprising a thermal element disposed adjacent the pilot burner so as to be actuated by heat therefrom, a lever arm operatively connecting the throttle valve and the thermal element, said lever arm extending through an opening in the throttle valve housing, and a sealingdiaphragm disposed across the opening for sealing the opening and providing a fulcrum for the lever arm.

JOHN C. ENGLISH. 

